.book {
  -webkit-transition: opacity 0.4s 0.2s;
  transition: opacity 0.4s 0.2s;
}

.page {
  width: 30vw;
  height: 42vw;
  background-colour: #ffffff;
  float: left;
  margin-bottom: 0.5em;
}

.page:first-child {
  float: right;
}

.page:nth-child(even) {
  clear: both;
}

.bound {
  -webkit-perspective: 250vw;
  perspective: 250vw;
}

.bound .pages {
  width: 60vw;
  height: 42vw;
  position: relative;
  -webkit-transform: rotateX(12deg);
  transform: rotateX(12deg);
  -webkit-transform-style: preserve-3d;
  transform-style: preserve-3d;
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
  border-radius: 4px;
  box-shadow: 0 0 0 1px #e3dfd8;
}

.bound .page {
  float: none;
  clear: none;
  margin: 0;
  position: absolute;
  top: 0;
  width: 30vw;
  height: 42vw;
  -webkit-transform-origin: 0 0;
  -ms-transform-origin: 0 0;
  transform-origin: 0 0;
  -webkit-transition: -webkit-transform 1.4s;
  transition: transform 1.4s;
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
  -webkit-transform-style: preserve-3d;
  transform-style: preserve-3d;
  cursor: pointer;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
}

.bound .page:before {
  content: '';
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  background: rgba(0, 0, 0, 0);
  -webkit-transition: background 0.7s;
  transition: background 0.7s;
  z-index: 2;
}

.bound .page:nth-child(odd) {
  pointer-events: all;
  -webkit-transform: rotateY(0deg);
  transform: rotateY(0deg);
  right: 0;
  border-radius: 0 4px 4px 0;
}

.bound .page:nth-child(odd):hover {
  -webkit-transform: rotateY(-10deg);
  transform: rotateY(-10deg);
}

.bound .page:nth-child(odd):hover:before {
  background: rgba(0, 0, 0, 0.03);
}

.bound .page:nth-child(odd):before {
  background: rgba(0, 0, 0, 0);
}

.bound .page:nth-child(even) {
  pointer-events: none;
  -webkit-transform: rotateY(180deg);
  transform: rotateY(180deg);
  -webkit-transform-origin: 100% 0;
  -ms-transform-origin: 100% 0;
  transform-origin: 100% 0;
  left: 0;
  border-radius: 4px 0 0 4px;
}

.bound .page:nth-child(even):before {
  background: rgba(0, 0, 0, 0.2);
}

.bound .page.grabbing {
  -webkit-transition: none;
  transition: none;
}

.bound .page.flipped:nth-child(odd) {
  pointer-events: none;
  -webkit-transform: rotateY(-180deg);
  transform: rotateY(-180deg);
}

.bound .page.flipped:nth-child(odd):before {
  background: rgba(0, 0, 0, 0.2);
}

.bound .page.flipped:nth-child(even) {
  pointer-events: all;
  -webkit-transform: rotateY(0deg);
  transform: rotateY(0deg);
}

.bound .page.flipped:nth-child(even):hover {
  -webkit-transform: rotateY(10deg);
  transform: rotateY(10deg);
}

.bound .page.flipped:nth-child(even):hover:before {
  background: rgba(0, 0, 0, 0.03);
}

.bound .page.flipped:nth-child(even):before {
  background: rgba(0, 0, 0, 0);
}

*,
* :before,
*:after {
  box-sizing: border-box;
}

html,
body {
  background: #e3dfd8;
  -webkit-tap-highlight-color: rgba(0, 0, 0, 0);
}

html {
  height: 100%;
}

body {
  min-height: 100%;
  display: -webkit-box;
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-pack: center;
  -webkit-justify-content: center;
  -ms-flex-pack: center;
  justify-content: center;
  -webkit-box-align: center;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  padding: 2em 0;
  font-family: menlo, monospace;
  line-height: 1.5em;
}

.page {
  line-height: 27vw;
  text-align: center;
}

.page {
  color: transparent;
  background: left top no-repeat;
  background-size: cover;
}

.page:nth-child(3),
.page:nth-child(5),
.page:nth-child(7),
.page:nth-child(9),
.page:nth-child(11),
.page:nth-child(13),
.page:nth-child(15),
.page:nth-child(17),
.page:nth-child(19),
.page:nth-child(21),
.page:nth-child(23),
.page:nth-child(25),
.page:nth-child(27),
.page:nth-child(29),
.page:nth-child(31),
.page:nth-child(33),
.page:nth-child(35),
.page:nth-child(37),
.page:nth-child(39),
.page:nth-child(41),
.page:nth-child(43),
.page:nth-child(45),
.page:nth-child(47),
.page:nth-child(49),
.page:nth-child(51),
.page:nth-child(53),
.page:nth-child(55),
.page:nth-child(57),
.page:nth-child(59),
.page:nth-child(61),
.page:nth-child(63),
.page:nth-child(65) {
  background-position: right top;
}

.page:nth-child(1) {
  background-image: url('../images/fengmian.jpg');
}

.page:nth-child(2),
.page:nth-child(3) {
  background-image: url('../images/0-0.jpg');
}

.page:nth-child(4),
.page:nth-child(5) {
  background-image: url('../images/0-1.jpg');
}

.page:nth-child(6),
.page:nth-child(7) {
  background-image: url('../images/2-3.jpg');
}

.page:nth-child(8),
.page:nth-child(9) {
  background-image: url('../images/4-5.jpg');
}

.page:nth-child(10),
.page:nth-child(11) {
  background-image: url('../images/6-7.jpg');
}

.page:nth-child(12),
.page:nth-child(13) {
  background-image: url('../images/8-9.jpg');
}

.page:nth-child(14),
.page:nth-child(15) {
  background-image: url('../images/10.jpg');
}

.page:nth-child(16),
.page:nth-child(17) {
  background-image: url('../images/10-11.jpg');
}

.page:nth-child(18),
.page:nth-child(19) {
  background-image: url('../images/12-13.jpg');
}

.page:nth-child(20),
.page:nth-child(21) {
  background-image: url('../images/14-15.jpg');
}

.page:nth-child(22),
.page:nth-child(23) {
  background-image: url('../images/16-17.jpg');
}

.page:nth-child(24),
.page:nth-child(25) {
  background-image: url('../images/18-19.jpg');
}

.page:nth-child(26),
.page:nth-child(27) {
  background-image: url('../images/20-21.jpg');
}

.page:nth-child(28),
.page:nth-child(29) {
  background-image: url('../images/22-23.jpg');
}

.page:nth-child(30),
.page:nth-child(31) {
  background-image: url('../images/24-25.jpg');
}

.page:nth-child(32),
.page:nth-child(33) {
  background-image: url('../images/26-27.jpg');
}

.page:nth-child(34),
.page:nth-child(35) {
  background-image: url('../images/28-29.jpg');
}

.page:nth-child(36),
.page:nth-child(37) {
  background-image: url('../images/30-31.jpg');
}

.page:nth-child(38),
.page:nth-child(39) {
  background-image: url('../images/32-33.jpg');
}

.page:nth-child(40),
.page:nth-child(41) {
  background-image: url('../images/34-35.jpg');
}

.page:nth-child(42),
.page:nth-child(43) {
  background-image: url('../images/36-37.jpg');
}

.page:nth-child(44),
.page:nth-child(45) {
  background-image: url('../images/38-39.jpg');
}

.page:nth-child(46),
.page:nth-child(47) {
  background-image: url('../images/40-41.jpg');
}

.page:nth-child(48),
.page:nth-child(49) {
  background-image: url('../images/42-43.jpg');
}

.page:nth-child(50),
.page:nth-child(51) {
  background-image: url('../images/44-45.jpg');
}

.page:nth-child(52),
.page:nth-child(53) {
  background-image: url('../images/46-47.jpg');
}

.page:nth-child(54),
.page:nth-child(55) {
  background-image: url('../images/48-49.jpg');
}

.page:nth-child(56),
.page:nth-child(57) {
  background-image: url('../images/50.jpg');
}

.page:nth-child(58),
.page:nth-child(59) {
  background-image: url('../images/51-52.jpg');
}

.page:nth-child(60),
.page:nth-child(61) {
  background-image: url('../images/53-54.jpg');
}

.page:nth-child(62),
.page:nth-child(63) {
  background-image: url('../images/55-56.jpg');
}

.page:nth-child(64),
.page:nth-child(65) {
  background-image: url('../images/57-58.jpg');
}

.page:nth-child(66) {
  background-image: url('../images/fengdi.jpg');
}